Mapping the upper mantle structure beneath the South Atlantic and the adjacent continents using full waveform tomography with geodynamic interpretations of hotspot flux and material transport in the asthenosphere.

使用全波形断层扫描绘制南大西洋和邻近大陆下方的上地幔结构图，并对软流圈中的热点通量和物质传输进行地球动力学解释。

• 批准号: 172686521
• 负责人: Professor Dr. Hans-Peter Bunge, Ph.D.
• 金额: --
• 依托单位: Eidgenössische Technische Hochschule Zürich (ETH)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/172686521?language=en
• 关键词: Mapping; upper; mantle; structure; beneath

We propose to combine full waveform tomography and geodynamic forward modelling to address key questions concerning the geodynamics and evolution of the South Atlantic region: (1) How and to which extent does the South Atlantic plume system feed the asthenosphere in the oceanic basin and adjacent regions? (2) What are the current thermal states of the Walvis Ridge and the Etendeka and Paraná continental flood basalt? (3) What, if any, is the pathway of slow seismic material from the upper to the lower mantle? (4) Is the prominent topographic gradient across the South Atlantic region from Africa to South America explicable solely in terms of lower mantle structure, or do we also find a systematic gradient in upper mantle heterogeneity across the ocean basin? (5) What is the relation of upper mantle heterogeneity and anisotropic structure to the Mid-Atlantic ridge system and hotspots? The use of full waveform tomography will allow us to exploit as much information as possible from seismograms. Our approach is thus well suited for regions with comparatively low data coverage such as the South Atlantic. Mineral physics models will allow us to infer dynamically important constraints on lateral temperature variations in a thermodynamically self-consistent way from the seismic observations. Observations of seismic anisotropy and geodynamic modelling will help us to further quantify and substantiate our inferences on the thermal state and material flux in the South Atlantic upper mantle.

我们建议结合联合收割机全波形层析成像和地球动力学正演模拟，以解决有关的地球动力学和演化的南大西洋地区的关键问题：（1）如何以及在何种程度上南大西洋羽系统饲料软流圈在洋盆和邻近地区？(2)沃尔维斯海岭和埃滕德卡及巴拉那大陆溢流玄武岩目前的热状态如何？(3)如果有的话，慢地震物质从上地幔到下地幔的路径是什么？(4)从非洲到南美洲横跨南大西洋地区的显著地形梯度仅仅可以用下地幔结构来解释，还是我们也发现了横跨洋盆的上地幔不均匀性的系统梯度？(5)上地幔的不均匀性和各向异性结构与中大西洋海岭系统和热点有什么关系？全波形层析成像的使用将使我们能够利用尽可能多的信息，从地震图。因此，我们的方法非常适合数据覆盖率相对较低的地区，如南大西洋。矿物物理模型将使我们能够从地震观测中以一种自洽的方式推断出对横向温度变化的动态重要约束。对地震各向异性和地球动力学模型的观测将有助于我们进一步量化和证实我们对南大西洋上地幔热状态和物质通量的推断。